The aim of this project is to establish the biosynthetic pathway for the formation of azetidine-2-carboxylic (A-2-C) acid in the microorganism Actinoplanes ferrugineus and further to elucidate the steric course of the formation of A-2-C from the appropriately labeled precursor. Regio- and stereo-specific isotopically labeled substrates and products (A-2-C) will be used to gain information concerning the mechanism of this enzyme. The total steric course of the enzyme reaction will be elucidated from the sum of the individual stereochemical events occurring at the Alpha-, Beta-, and Gamma-carbons of each substrate amino acid. Both enzymatic and chemical methodology will be utilized to synthesize the regio- and stereo-specific 13C- and 2H-labeled substrate amino acids and A-2-C. The configuration of the substrate, products, etc. will be determined using a combination of 1H-, 2H- and 13C-NMR, mass spec. and ORD and CD.